USSG stands for United States Sentencing Guidelines. As a captain you are responsible for the safety of your passengers. On my own time if I want to drink 10 rum punches and go swimming on a deserted beach, most likely no one will be held responsible if I am found dead the next day. If I allow that on my boat, I am responsible.If I over serve someone on my boat and nothing happens on the water, but they get off the dock, get into their car, and kill someone, I can also be held liable. If I beat the charges, but this becomes a rumor, will anyone charter with me?
I am all for fun, and I like a good time as much as the next guy, but on the water, or in car, you are responsible for the lives of your passengers, which means sometimes saying no for their own benefit.
As far as kayaking, you said it was your first time. That skin is not used to getting the workout it did. Kind of like muscles that you do not use often.Next time use gloves, or kayak more so your skin gets adapted and your technique becomes smoother.
As far as the music is concerned, you can ask if they would, but they are not obliged to, and like others have said they have to please all their guests. No offense.